conchiolin

 
Pronunciation: /ˈkɒntʃɪə(ʊ)lɪn/

noun

[mass noun] Zoology
  • a tough, insoluble protein secreted by molluscs, forming the organic matrix of the shell within which calcium carbonate is deposited.

Origin:

late 19th century: from Latin concha 'shell' + the diminutive suffix -iola + -in1